II. Epidemiology

  1. Prevalence
    1. Meconium-stained amniotic fluid is present in up to 15% of deliveries
    2. Meconium Aspiration Syndrome occurs in only 1% of all deliveries

III. Pathophysiology

  1. Meconium contains gastrointestinal fluids which cause localized inflammation
  2. Meconium Aspiration results in severe airway inflammation and Pneumonia risk
  3. Meconium Aspiration occurs in utero, not at delivery

IV. Signs

  1. Hypoxia and Cyanosis
  2. Respiratory distress
    1. Tachypnea
    2. Grunting
    3. Retractions
  3. Lung Exam
    1. Rales and rhonchi
    2. Chest may appear barrel-shaped

V. Differential Diagnosis

VI. Imaging: Chest XRay

  1. Patchy Atelectasis (fluffy densities)
  2. Hyperinflation
  3. Lung consolidation changes

VII. Management: Meconium stained infant

  1. See Respiratory Distress in the Newborn
  2. See Newborn Resuscitation
  3. Infant brought to warmer with head angled down and with minimal stimulation
  4. Oxygenation and ventilation
    1. Supplemental Oxygen 21-50% FIO2 to keep Oxygen Saturation >90%
    2. Non-Invasive Positive Pressure Ventilation (e.g. N-CPAP)
    3. Endotracheal Intubation may be required
  5. Evaluate infant for vigorous activity
    1. Vigorous infants without distress may be managed routinely
    2. Infants with Heart Rate <100 beats/min, apnea, or poor tone require intervention
      1. Intubation
      2. Suctioning

VIII. Prevention

  1. Suctioning head at the perineum no longer recommended
    1. See pathophysiology above regarding in utero aspiration
    2. Vain (2004) Lancet 364:597-602 [PubMed]
  2. Amnioinfusion does not decrease Meconium Aspiration risk
    1. Fraser (2005) N Engl J Med 353:909-17 [PubMed]

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Ontology: Meconium Aspiration Syndrome (C0025048)

Definition (NCI) A serious condition in which a newborn breathes a mixture of meconium (the first intestinal discharge) and amniotic fluid into the lungs around the time of delivery. Meconium aspiration syndrome occurs in 5-10 percent of births and typically occurs when the infant is stressed, as when the infant is past its due date.
Definition (MSH) A condition caused by inhalation of MECONIUM into the LUNG of FETUS or NEWBORN, usually due to vigorous respiratory movements during difficult PARTURITION or respiratory system abnormalities. Meconium aspirate may block small airways leading to difficulties in PULMONARY GAS EXCHANGE and ASPIRATION PNEUMONIA.
Concepts Pathologic Function (T046)
MSH D008471
ICD10 P24.0 , P24.00, P24.01
SnomedCT 14608006, 85779008, 157110000, 278927005, 206292002
English Neonatal aspiration meconium, MAS - Meconium aspir syndrome, aspiration of meconium, meconium aspiration, aspiration of meconium (diagnosis), meconium aspiration syndrome (diagnosis), meconium aspiration syndrome, Meconium Inhalation, Meconium aspiration, MAS, Meconium Aspiration Syndrome, Meconium aspiration NOS, Meconium aspiration syndrome NOS, Meconium Aspiration Syndrome [Disease/Finding], aspiration meconium, of meconium aspiration, meconium aspirations, aspiration meconium syndrome, Neonatal Aspiration of Meconium, Aspiration of meconium (disorder), Meconium aspiration syndrome (finding), Aspiration of meconium, Meconium aspiration syndrome, Neonatal aspiration of meconium, MAS - Meconium aspiration syndrome, Meconium aspiration syndrome (disorder), Neonatal aspiration of meconium (disorder), aspiration; meconium, aspiration; newborn, meconium, aspiration; syndrome of newborn, meconium, inhalation; meconium, meconium; aspiration, meconium; inhalation, syndrome; aspiration, of newborn, meconium, Meconium aspiration syndrome (finding) [Ambiguous], Aspiration of meconium -RETIRED-, Aspiration, Meconium, Meconium Aspiration, Aspiration Syndrome, Meconium, Syndrome, Meconium Aspiration
Dutch meconiumaspiratie, aspiratie; meconium, aspiratie; pasgeborene, meconium, aspiratie; syndroom van pasgeborene, meconium, inhalatie; meconium, meconium; aspiratie, meconium; inhalatie, syndroom; aspiratie, van pasgeborene, meconium, Neonatale aspiratie van meconium, Aspiratie, meconium-, Meconiumaspiratie
Portuguese Aspiração de mecónio, Síndrome de Aspiração Meconial, Síndrome de Aspiração do Mecônio, Síndrome de Aspiração de Mecônio
Spanish Aspiración de meconio, síndrome de aspiración meconial, aspiración de meconio - RETIRADO - (concepto no activo), aspiración de meconio - RETIRADO -, síndrome de aspiración meconial (hallazgo), aspiración de meconio, aspiración neonatal de meconio (trastorno), aspiración neonatal de meconio, síndrome de aspiración de meconio (trastorno), síndrome de aspiración de meconio, síndrome de aspiración meconial (concepto no activo), síndrome meconial, Síndrome de Aspiración de Meconio
Swedish Mekoniumaspirationssyndrom
Japanese タイベンキュウイン, 胎便吸引症候群, 吸引-胎便, 大量吸引症候群, 羊水過度吸引, 羊水過度吸引症候群, 胎便吸引
Czech mekonium - aspirace, syndrom aspirace mekonia, Aspirace mekonia
Finnish Mekoniumaspiraatio
Russian ASPIRATSIIA MEKONIIA, MEKONIIA ASPIRATSII SINDROM, MEKONIIA ASPIRATSIIA, АСПИРАЦИЯ МЕКОНИЯ, МЕКОНИЯ АСПИРАЦИЯ, МЕКОНИЯ АСПИРАЦИИ СИНДРОМ
German Mekoniumaspiration durch das Neugeborene, Aspiration, Mekonium-, Mekoniumaspiration
Korean 태변의 신생아 흡인
Polish Zespół aspiracji smółki
Hungarian Meconium aspiratio
Norwegian Mekoniumaspirasjonssyndrom, Mekoniumaspirasjon
French Inhalation amniotique, Inhalation de méconium, Inhalation méconiale, Syndrome d'inhalation méconiale
Italian Aspirazione di meconio

Ontology: Meconium pneumonitis (C0270155)

Concepts Disease or Syndrome (T047)
ICD10 P24.01
SnomedCT 86649001
English meconium aspiration pneumonitis (diagnosis), meconium aspiration pneumonitis, Meconium aspiration pneumonitis, Meconium pneumonitis, Meconium pneumonitis (disorder), aspiration pneumonitis; meconium, meconium; aspiration pneumonitis, meconium; pneumonitis, pneumonitis; meconium
Dutch aspiratiepneumonie; meconium, meconium; aspiratiepneumonie, meconium; pneumonitis, pneumonitis; meconium
Spanish neumonitis meconial, neumonitis por meconio (trastorno), neumonitis por meconio

Ontology: meconium aspiration pneumonia (C1388846)

Concepts Disease or Syndrome (T047)
ICD10 P24.01
English meconium aspiration pneumonia (diagnosis), meconium aspiration pneumonia, Meconium aspiration pneumonia, meconium; pneumonia, pneumonia; aspiration, meconium, pneumonia; meconium
Dutch meconium; pneumonie, pneumonie; aspiratie, meconium, pneumonie; meconium